Idk if this has been posted already, but I saw no threads specifically about it on the first page so w.e
Anyway, I think I got it.
1) I think it's about the fans for the most part.
Eminem - Lots of his fans 'kicked him when he was down' by attacking what he did with Encore and Relapse. Fans and other people alike have for years been talking about how bad Encore was, and many people attack Relapse as well. So he's saying these people get 'No Love' from him because if you aren't going to stand by him during a slump, then fuck you.
Wayne - Lots of his fans have been 'kicking him when he was down' by attacking what he did on Rebirth, and a ton of haters have acted like they were glad he was going to jail and shit. "Okay, you want me up in a cage, then I'll come out in beast mode" to prove these people wrong, that he can actually still burn people on the mic. Also Many fans said C3 was garbage, so the same applies to that.
Basically, they came out on this song to say fuck all you non-believers, we don't need you, and look at you probably come back riding our dicks after this.